Developmental aspects of sleep in Prader Willi Syndrome

Abstract

Background: Children with Prader Willi syndrome (PWS) are at risk of sleep disordered breathing involving central and obstructive components. PWS patients are known to have abnormal responses to hypoxia and hypercapnoea, an increased incidence of Obstructive Sleep Apnoea [OSA] and hypersomnolence when older. As infants, many present with delay in central control of breathing during sleep and resultant hypoxia. This may have long term consequences for the phenotype. Methods: Polysomnography (PSG) and multiple sleep latency testing [MSLT] was performed on PWS children attending a multidisciplinary clinic. Sleep disorders and age of presentation were identified. EEG spectral analysis on infants was undertaken and compared to a group of typically developing infants. Genotype was established. Results: Results suggest that in children less than 2 years central hypoventilation is present in 100%. 10% of children older than five had normal studies and the rest had OSA+/central hypoventilation. 10% had central hypoventilation and hypersomnolence. Twenty‐five children under 12 months of age were analysed separately. Improvements in central hypoventilation were seen in some infants as they matured. The relationship between this and development of mature EEG patterns was examined and is significantly different to EEG spectral analysis of normal infants studied at 3, 6 and 12 months. This was also related to the genotype of each infant. Conclusion: Infants with Prader Willi have a delay in neural maturity as reflected by EEG development of defined EEG sleep stages. All infants with Prader Willi should have a sleep study in infancy and appropriate therapy instigated if required. Hypersomnolence is generally associated with other sleep disorders.